A fine-needle aspiration (FNA) may be needed to detect a thyroid nodule. You may be a little worried and scared when you hear that you have to “stick a needle in your neck”. In fact, the doctor will strictly evaluate the indications and contraindications before the procedure. As long as you are not overly nervous and cooperate with the doctor, this test is safe for most patients. Here is how you, as a patient, need to cooperate with your doctor.
How is this test done? Is it painful?
The FNA is usually done at the time of the test.
FNA is usually done under ultrasound guidance. The doctor uses a long, thin needle to pinpoint the nodule, aspirates the cells, makes a smear, and then looks at it under a microscope to determine the benignity or malignancy of the thyroid nodule by the cell pattern.
Before puncturing, the doctor performs an ultrasound to understand the location and size of the nodule and the distribution of surrounding blood vessels, and determines a good path to the needle, avoiding larger vessels.
It is important to note that punctures are usually performed without anesthetic. The puncture needle is very thin and usually not too painful.
If the nodule is in a good location (e.g., the nodule is on the surface of the thyroid), then the test can be done quickly and painlessly, just like a normal injection or blood draw. Sometimes the nodules are poorly located (e.g., nodules on the dorsal side of the thyroid or near large blood vessels), smaller, or have multiple lesions that need to be punctured, then the procedure may be more difficult and take longer, and the whole process may feel more painful.
What do you need to do to prepare for the test?
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- The puncture site is in the neck, so wear clothes without a collar or that open easily to the neck and do not wear jewelry
- Sit and rest and relax before the puncture
- Puncture may not be possible if you have a coagulation disorder or if you have been taking anticoagulant medication (e.g. warfarin) for a long time, or you may need to stop taking the medication and then puncture again, so inform your doctor in advance
- If you have heart failure or cardiopulmonary disease, you will need to have your heart and lung function adjusted in advance in the internal medicine department because you will need to lie down and not cough frequently or vigorously during the puncture
How should you cooperate during the test?
While the doctor is performing the puncture, you will need to lie in a supine position and keep your neck tilted back to fully expose your neck. Try to keep your neck still, do not talk, cough, or swallow to minimize thyroid movement.
What to look for after the checkup?
- After the puncture, the pain level is about the same as during the blood draw, and most people do not need any pain medication. If you are more sensitive to pain and find it unbearable, you may take pain medication. Be careful to avoid pain medications that contain aspirin, as there may be an increased risk of bleeding.
- Because the wound is only the size of the tip of a needle, a bandage is not needed after the puncture.
- You can perform daily tasks, driving and outdoor activities after the puncture, taking care not to perform strenuous physical activities such as weight lifting.
What are the possible risks of FNA?
Fine needle aspiration is a safe and reliable test that generally has no complications, but it is, after all, an invasive procedure and the following risks may occur:
Subcutaneous or subperitoneal hematoma of the thyroid gland
The incidence is low and usually not serious. Bleeding can be reduced by applying more pressure for a few moments after the puncture. A small bleeding hematoma can resolve within a few days without special treatment.
Infection
The incidence is also low because of the aseptic nature of the procedure. If it occurs, it can be treated with antibiotics as prescribed by your doctor.
Local discomfort or pain
A small number of people experience mild pain or discomfort after puncture, which usually does not need to be treated. If the pain is unbearable, it can be managed with appropriate pain medication under medical supervision and usually gets better within a few days.
Tracheal injury
If the tip of the needle hits the trachea during the puncture, it may cause coughing or coughing up blood, which is usually not serious. At this time, you should rest quietly, avoid excessive stress, and seek medical attention if necessary.
Vascular injury in the neck
It may cause damage to blood vessels in the neck, usually small ones, and can be treated with hand pressure to stop the bleeding.
Nerve injury
May cause hoarseness. This is a rare condition that tends to subside on its own and requires no special treatment.
Co-written by Dr. Yiming Cao, Cancer Hospital of Fudan University